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authorAmitkumar Karwar <akarwar@marvell.com>2013-10-23 00:24:44 +0200
committerJohn W. Linville <linville@tuxdriver.com>2013-11-11 20:38:56 +0100
commitfe1c9a443e0d1e0af790883f091fb1c4f418bc8f (patch)
tree5bb5700952ca24730ebd1f253353290d38a29b0e
parentmwifiex: replace u16 with __le16 in struct mwifiex_types_power_group (diff)
downloadlinux-fe1c9a443e0d1e0af790883f091fb1c4f418bc8f.tar.xz
linux-fe1c9a443e0d1e0af790883f091fb1c4f418bc8f.zip
mwifiex: fix invalid memory access in mwifiex_get_power_level()
With "while (length)" check we may end up in accessing invalid memory in last iteration. This patch makes sure that tlv length is not less than the length of structure mwifiex_power_group when min/max power is calculated. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Amitkumar Karwar <akarwar@marvell.com> Signed-off-by: Bing Zhao <bzhao@marvell.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--drivers/net/wireless/mwifiex/sta_cmdresp.c22
1 files changed, 12 insertions, 10 deletions
diff --git a/drivers/net/wireless/mwifiex/sta_cmdresp.c b/drivers/net/wireless/mwifiex/sta_cmdresp.c
index bdf50fd5ef6b..5edea4dd05a8 100644
--- a/drivers/net/wireless/mwifiex/sta_cmdresp.c
+++ b/drivers/net/wireless/mwifiex/sta_cmdresp.c
@@ -341,12 +341,16 @@ static int mwifiex_get_power_level(struct mwifiex_private *priv, void *data_buf)
pg = (struct mwifiex_power_group *)
((u8 *) pg_tlv_hdr + sizeof(struct mwifiex_types_power_group));
length = le16_to_cpu(pg_tlv_hdr->length);
- if (length > 0) {
- max_power = pg->power_max;
- min_power = pg->power_min;
- length -= sizeof(struct mwifiex_power_group);
- }
- while (length) {
+
+ /* At least one structure required to update power */
+ if (length < sizeof(struct mwifiex_power_group))
+ return 0;
+
+ max_power = pg->power_max;
+ min_power = pg->power_min;
+ length -= sizeof(struct mwifiex_power_group);
+
+ while (length >= sizeof(struct mwifiex_power_group)) {
pg++;
if (max_power < pg->power_max)
max_power = pg->power_max;
@@ -356,10 +360,8 @@ static int mwifiex_get_power_level(struct mwifiex_private *priv, void *data_buf)
length -= sizeof(struct mwifiex_power_group);
}
- if (le16_to_cpu(pg_tlv_hdr->length) > 0) {
- priv->min_tx_power_level = (u8) min_power;
- priv->max_tx_power_level = (u8) max_power;
- }
+ priv->min_tx_power_level = (u8) min_power;
+ priv->max_tx_power_level = (u8) max_power;
return 0;
}